1. Field of the Invention
The present invention relates to an antenna element, and in particular, to an antenna element in which an antenna defined by a conductive pattern is provided in a laminate and a method of manufacturing the antenna element.
2. Description of the Related Art
Antenna elements included in small electronic devices such as communication terminal devices commonly have a structure in which an antenna defined by a conductive pattern is provided on an insulating base.
In recent years, due to increasingly thinner and smaller electronic devices having such an antenna element incorporated therein, it is usually necessary to dispose the antenna element at a position away from a circuit board within the limited space of the housing of the electronic device. It is thus preferable to mold the antenna element not in a simple rectangular parallelepiped shape but in a shape suitable of being accommodated in the housing.
As described in, for example, WO 2014/042070, a method has been employed in which an antenna defined by a plated film pattern is directly formed on the surface of a resin mold using the Laser Direct Structuring (LDS) process.
The LDS process mentioned above irradiates laser light onto the surface of a resin mold containing an LDS additive and activates only the portion of the surface irradiated by the laser light to selectively form a plated film on the activated part. The LDS process enables a conductive pattern to be formed particularly on the surface of the resin mold with recesses and protrusions, and thus has an advantage of being capable of molding an antenna element that is usually disposed at the end of a housing in a shape conforming to the shape of the housing.
However, it is necessary to perform a step of applying a catalyst activated by laser light on a resin mold and thus a manufacturing process is complicated. Additionally, a resin used as an insulator is easily modified and thus antenna characteristics may be degraded.